406 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
location the remains occur in the deposits of a vestigial valley bottom 
that has taken on the appearance of a terrace as a result of the eroding 
of the ridges that once bordered its southern side (pl. 4, fig. 1). 
By correlating the occupation level, which is in the bottom of, or 
just below, a dark-soil zone that was formed during a wet cycle 
(pl. 4, fig. 2), with the terraces of the main drainage streams, and 
those, in turn, with traces of glacial stages in the mountains on the 
west, it was demonstrated that the period of the archeological re- 
mains was near the close of the Pleistocene (Bryan and Ray, 1940). 
Approximately the same geologic horizon is indicated in all three 
cases and this is corroborated by evidence from several smaller sites. 
As a consequence the belief that the Folsom Complex developed 
toward the end of the Pleistocene or late glacial period and carried 
over into the beginning of the Recent is now more or less generally 
accepted. 
A majority of the Folsom remains and sporadic traces of the com- 
plex are found in the eastern part of the continent. Some have been 
reported from the Great Basin—the plateau area comprising western 
Utah, most of the State of Nevada, and southeastern California— 
lying between the Wasatch Mountains and the Sierra Nevadas, and a 
few points have been found in northern California where there is 
one possible small site. Most of the material, however, is in the area 
extending from Alberta and Saskatchewan in Canada on the north 
to southern New Mexico in the south, from the eastern slopes of the 
Rocky Mountains on the west to an eastern border that follows 
roughly the western boundary of the Dakotas, cuts across western 
Nebraska, Kansas, Oklahoma, and thence into Texas, where it turns 
eastward to the Mississippi River. There are indications of smaller 
centers in the region around the junctures of the Missouri and Ohio 
Rivers with the Mississippi, in Ohio, western New York, western 
Pennsylvania, Virginia, Tennessee, Georgia, and northern North 
Carolina. An old medicine man in Sonora, Mexico, is reported to 
carry two such points in his bag of fetishes. ‘There is no informa- 
tion, however, on how he obtained them or where they were found, and 
they have no value as evidence. The distribution of Folsom imple- 
ments implies that there must have been some specific relationship 
between the physical environment, the hunting economy basis of the 
cultural pattern, and the period when the spread took place. The 
latter will be considered in subsequent discussion, as it also has a bear- 
ing on some of the other types of remains. 
Papers pertaining to the general subject of the Paleo-Indian fre- 
quently link another group of points with the Folsom series (pl. 5, 
fig. 1). They are called Yuma from the county in eastern Colorado 
where the first examples were found. The two forms were at first 
